Hen's egg allergen in house and bed dust is significantly increased after hen's egg consumption-A pilot study.

Environmental exposure to food allergens may be a risk factor for cutaneous sensitization. Previous studies could detect peanut allergen in house dust. In this pilot study, we wanted to investigate whether hen's egg allergen is detectable in house dust collected from different household areas and whether levels are increased after intentional hen's egg consumption. Hen's egg protein levels of dust samples were measured using ELISA. In 8 of 8 households, hen's egg was detectable in dust samples of eating area and bed. Forty-eight hours after intentional hen's egg consumption, hen's egg protein levels were significantly increased in both. Still, further research is necessary to investigate whether hen's egg allergen in house and bed dust plays a role in sensitization via skin.

Natural tolerance development in cow's milk allergic children: IgE and IgG4 epitope binding.

BACKGROUND: Although most of cow's milk (CM) allergic children will outgrow their allergy, the pathomechanism of the natural development of tolerance remains poorly understood. It has been suggested that the balance between milk-specific IgE and IgG4 plays a major role. OBJECTIVE: We aimed to investigate differences in IgE and IgG4 antibody binding to CM epitopes between patients with persistent CM allergy (CMA) and those that naturally became tolerant. METHODS: Sera from 35 children with proven CMA (median age at inclusion of 10 months) were analyzed retrospectively; 22 patients have become tolerant (median age at tolerance acquisition of 51 months) during the study period as confirmed by a negative oral food challenge. IgE and IgG4 binding to sequential epitopes derived from five major CM proteins were measured with a peptide microarray-based immunoassay. RESULTS: At baselines, greater intensity and broader diversity of IgE and IgG4 binding have been found in children with persistent CMA beyond 5 years of age compared to patients with transient CMA. Moreover, children with transient CMA had IgE and IgG4 antibodies that more often recognized the same epitopes, compared to those with persistent CMA. From baseline to the time of tolerance development, both IgE and IgG4 binding intensity decreased significantly, particularly in areas of α-s- and ß-casein (P<.01, false discovery rate [FDR]<.1). Interestingly, differences between IgE and IgG4 binding intensity to CM peptides decreased when the patients became tolerant. CONCLUSIONS: Our results suggest that the overlap between IgE and IgG4 might be important in natural tolerance acquisition. Further studies are needed to confirm our data and can eventually lead to development of more targeted treatment of food allergy.

Performance of a polymer coated silicon microarray for simultaneous detection of food allergen-specific IgE and IgG4.

BACKGROUND: Microarray-based component-resolved diagnostics (CRD) has become an accepted tool to detect allergen-specific IgE sensitization towards hundreds of allergens in parallel from one drop of serum. Nevertheless, specificity and sensitivity as well as a simultaneous detection of allergen-specific IgG4 , as a potential parameter for tolerance development, remain to be optimized. OBJECTIVE: We applied the recently introduced silicon chip coated with a functional polymer named copoly(DMA-NAS-MAPS) to the simultaneous detection of food allergen-specific IgE and IgG4 , and compared it with ImmunoCAP and ImmunoCAP ISAC. Inter- and intraslide variation, linearity of signal and working range, sensitivity and application of internal calibrations for IgE and IgG4 were assessed. METHODS: Native and recombinant allergenic proteins from hen's egg and cow's milk were spotted on silicon chips coated with copoly(DMA-NAS-MAPS) along with known concentrations for human IgE and IgG4 . A serum pool and 105 patient samples were assessed quantitatively and semi-quantitatively with the ImmunoCAP and ImmunoCAP ISAC and correlated with IgE- and IgG4 -specific fluorescence on silicon microarrays. RESULTS: Allergen-specific IgE and IgG4 were detected in parallel using two fluorescent dyes with no crosstalk. Results from the ImmunoCAP correlated better with microarray fluorescence than with ImmunoCAP ISAC except for the allergen ovomucoid. The working range of the silicon microarray for total hen's egg-specific IgE was comparable to the range of 0.1 to >100 kUA /L of the ImmunoCAP system, whereas for total cow's milk, the silicon microarray was less sensitive. Detectable allergen-specific IgG4 could be determined only for low concentrations, but still correlated positively with ImmunoCAP results. CONCLUSIONS: We confirmed the ability of the polymer coated silicon microarray to be comparably sensitive to the ImmunoCAP ISAC for various food allergens. This suggests that the copoly(DMA-NAS-MAPS) microarray is a low-cost, self-producible alternative to the commercial ImmunoCAP ISAC in allergy research.

A new framework for the documentation and interpretation of oral food challenges in population-based and clinical research.

BACKGROUND: The conduct of oral food challenges as the preferred diagnostic standard for food allergy (FA) was harmonized over the last years. However, documentation and interpretation of challenge results, particularly in research settings, are not sufficiently standardized to allow valid comparisons between studies. Our aim was to develop a diagnostic toolbox to capture and report clinical observations in double-blind placebo-controlled food challenges (DBPCFC). METHODS: A group of experienced allergists, paediatricians, dieticians, epidemiologists and data managers developed generic case report forms and standard operating procedures for DBPCFCs and piloted them in three clinical centres. The follow-up of the EuroPrevall/iFAAM birth cohort and other iFAAM work packages applied these methods. RECOMMENDATIONS: A set of newly developed questionnaire or interview items capture the history of FA. Together with sensitization status, this forms the basis for the decision to perform a DBPCFC, following a standardized decision algorithm. A generic form including details about severity and timing captures signs and symptoms observed during or after the procedures. In contrast to the commonly used dichotomous outcome FA vs no FA, the allergy status is interpreted in multiple categories to reflect the complexity of clinical decision-making. CONCLUSION: The proposed toolbox sets a standard for improved documentation and harmonized interpretation of DBPCFCs. By a detailed documentation and common terminology for communicating outcomes, these tools hope to reduce the influence of subjective judgment of supervising physicians. All forms are publicly available for further evolution and free use in clinical and research settings.

Food-induced anaphylaxis and cofactors - data from the anaphylaxis registry.

Food allergens are frequent causes of anaphylaxis. In particular in children and adolescents they are the most frequent elicitors of severe allergic reactions, and in adults food allergens rank third behind insect venom and drugs. Since July 2006 severe allergic reactions from Germany, Austria, and Switzerland are collected in the anaphylaxis registry. Currently 78 hospitals and private practises are connected. From July 2006 until February 2009 1,156 severe allergic reactions were registered. Among children and adolescents (n = 187, age range from 3 months to 17 years) food allergens were the most frequent triggers, comprising 58% of cases. In the adult group (n = 968, 18 - 85 years) food allergens were in the third position (16.3%) behind insect venom and drugs. In children legumes (31%) and in particular peanuts were frequently responsible food allergens, followed by tree nuts (25%) with hazelnut being the most frequent elicitor. In adults fruits (13.4%) most often induced severe food-dependent anaphylaxis, but also animal products (12.2%); among these most frequently crustaceans and molluscs. Cofactors were often suspected in food-dependent anaphylaxis, namely in 39% of the adult group and in 14% of the pediatric group. In adults drugs (22%) and physical activity (10%) were reported to be the most frequent cofactors, in children physical activity was suspected in 8.7% and drugs in 2.6%. Concomitant diseases like atopic dermatitis, allergic asthma, or allergic rhinoconjunctivitis were reported in 78% of children and adolescents and in 67% of the adults. In conclusion, food-induced anaphylaxis, its cofactors and concomitant diseases are age-dependent. The data offers to identify risk factors of anaphylaxis.

Ana o 3-specific IgE is a good predictor for clinically relevant cashew allergy in children.

INTRODUCTION: Component-resolved diagnostics using specific IgE to 2 S albumins has shown to be a valuable new option in diagnostic procedure. Ana o 3 is a 2 S albumin from cashew. The aim of this study was to investigate the role of Ana o 3-specific serum IgE in the diagnosis of cashew allergy and to identify cut-off levels to replace oral food challenges. Moreover, the value of additional determination of total IgE has been investigated. METHODS: In a multicentre study, we analysed specific IgE to cashew extract and Ana o 3 as well as total IgE in children with suspected cashew allergy using the ImmunoCAP-FEIA and a standardized diagnostic procedure including oral challenges where indicated. RESULTS: A total of 61 patients were included in the study. Forty-two were allergic to cashew, and 19 were tolerant. In receiver operating curves, Ana o 3 discriminates between allergic and tolerant children better than cashew-specific IgE with an area under the curve of 0.94 vs 0.78. The ratio of Ana o 3-specific IgE to total IgE did not further improve the diagnostic procedure. Probability curves for Ana o 3-specific IgE have been calculated, and a 95% probability could be estimated at 2.0 kU/l. CONCLUSION: Specific IgE to Ana o 3 is a valuable tool for the diagnosis of cashew allergy. Considering its positive predictive value, it might allow to make a considerable number of oral challenges superfluous.

Horse Allergy: Curly Horses Allow Horse Allergic Riders To Ride Again.

To test the hypothesis that so called hypoallergenic horses (Curly horses) allow horse allergic riders to ride again, we investigated 40 horse allergic riders in a period of 37 months. Methods: We tested these patients (pts.) by skin prick test (SPT) with different non-curly and Curly horses and studied the riding hours and horse brushing by measurements of peak expiratory flow (PEF) and Tiffeneau tests (FEV1) as well as peak nasal inspiratory flow (PNIF) over 12 months. The results in 37/40 pts. showed no relevant reactions of the lower airways or nasal flow. Only in 3/40 patients an initial significant fall of FEV1 was observed, reversed by a single inhalation of salbutamol and not repeated despite further riding contact. In contrast to other allergic events (e. g. baker's asthma) a further and regular contact with these horses abolished the mild allergic reactions of the start period of contact. This may be due to hypoallergenic properties of these horses, whose test material produces weaker reactions in the SPT than that of normal horses. After a period of three years, a loss of reactivity to normal horses could be confirmed in some of the riders. Conclusion: The tested purebreed Curly horses may be a suitable alternative for horse allergic riders if the methodological precautions of this study are followed.

Detection of relevant amounts of cow's milk protein in non-pre-packed bakery products sold as cow's milk-free.

BACKGROUND: Currently, there is no mandatory labelling of allergens for non-pre-packed foods in the EU. Therefore, consumers with food allergy rely on voluntary information provided by the staff. The aim of this study was to characterize allergic reactions to non-pre-packed foods and to investigate whether staff in bakery shops were able to give advice regarding a safe product choice. METHODS: Questionnaires were sent to 200 parents of children with a food allergy. Staff of 50 bakery shops were interviewed regarding selling non-pre-packed foods to food-allergic customers. Bakery products being recommended as 'cow's milk-free' were bought, and cow's milk protein levels were measured using ELISA. RESULTS: A total of 104 of 200 questionnaires were returned. 25% of the children experienced an allergic reaction due to a non-pre-packed food from bakery shops and 20% from ice cream parlours. Sixty percent of the bakery staff reported serving food-allergic customers at least once a month, 24% once a week. Eighty four percent of the staff felt able to advise food-allergic consumers regarding a safe product choice. Seventy three 'cow's milk-free' products were sold in 44 bakery shops. Cow's milk could be detected in 43% of the bakery products, 21% contained >3 mg cow's milk protein per serving. CONCLUSION: Staff in bakery shops felt confident about advising customers with food allergy. However, cow's milk was detectable in almost half of bakery products being sold as 'cow's milk-free'. Every fifth product contained quantities of cow's milk exceeding an amount where approximately 10% of cow's milk-allergic children will show clinical relevant symptoms.

Predictive values of component-specific IgE for the outcome of peanut and hazelnut food challenges in children.

BACKGROUND: Oral challenges are the gold standard in food allergy diagnostic, but time-consuming. Aim of the study was to investigate the role of peanut- and hazelnut-component-specific IgE in the diagnostics of peanut and hazelnut allergy and to identify cutoff levels to make some challenges superfluous. METHODS: In a prospective and multicenter study, children with suspected peanut or hazelnut allergy underwent oral challenges. Specific IgE to peanut, hazelnut, and their components (Ara h 1, Ara h 2, Ara h 3, and Ara h 8, Cor a 1, Cor a 8, Cor a 9, and Cor a 14) were determined by ImmunoCAP-FEIA. RESULTS: A total of 210 children were challenged orally with peanut and 143 with hazelnut. 43% of the patients had a positive peanut and 31% a positive hazelnut challenge. With an area under the curve of 0.92 and 0.89, respectively, Ara h 2 and Cor a 14-specific IgE discriminated between allergic and tolerant children better than peanut- or hazelnut-specific IgE. For the first time, probability curves for peanut and hazelnut components have been calculated. A 90% probability for a positive peanut or hazelnut challenge was estimated for Ara h 2-specific IgE at 14.4 kU/l and for Cor a 14-specific IgE at 47.8 kU/l. A 95% probability could only be estimated for Ara h 2 at 42.2 kU/l. CONCLUSIONS: Ara h 2- and Cor a 14-specific IgE are useful to estimate the probability for a positive challenge outcome in the diagnostic work-up of peanut or hazelnut allergy making some food challenges superfluous.

Factors augmenting allergic reactions.

Elicitors of anaphylactic reactions are any sources of protein with allergenic capacity. However, not all allergic reactions end up in the most severe form of anaphylaxis. Augmenting factors may explain why certain conditions lead to anaphylaxis. Augmenting factors may exhibit three effects: lowering the threshold, increasing the severity, and reversing acquired clinical tolerance. Common augmenting factors are physical exercise, menstruation, NSAIDs, alcohol, body temperature, acute infections, and antacids. Therapeutic options may address causative, preventive, pragmatic, or symptomatic considerations: avoid the eliciting food, take an antihistamine before any situation with a possible risk of augmentation, separate food and sport (at least for 2 h), and carry an adrenaline autoinjector at all times. Individual patterns include summation effects and specific patterns. In conclusion, in the case of a suggestive history but a negative oral challenge, one should consider the possible involvement of augmenting factors; after anaphylactic reactions, always ask for possible augmentation and other risk factors during the recent past; if augmentation is suspected, oral food challenges should be performed in combination with augmenting factors; and in the future, standardized challenge protocols including augmenting factors should be established.

EAACI food allergy and anaphylaxis guidelines: diagnosis and management of food allergy.

Food allergy can result in considerable morbidity, impact negatively on quality of life, and prove costly in terms of medical care. These guidelines have been prepared by the European Academy of Allergy and Clinical Immunology's (EAACI) Guidelines for Food Allergy and Anaphylaxis Group, building on previous EAACI position papers on adverse reaction to foods and three recent systematic reviews on the epidemiology, diagnosis, and management of food allergy, and provide evidence-based recommendations for the diagnosis and management of food allergy. While the primary audience is allergists, this document is relevant for all other healthcare professionals, including primary care physicians, and pediatric and adult specialists, dieticians, pharmacists and paramedics. Our current understanding of the manifestations of food allergy, the role of diagnostic tests, and the effective management of patients of all ages with food allergy is presented. The acute management of non-life-threatening reactions is covered in these guidelines, but for guidance on the emergency management of anaphylaxis, readers are referred to the related EAACI Anaphylaxis Guidelines.

Anaphylaxis: guidelines from the European Academy of Allergy and Clinical Immunology.

Anaphylaxis is a clinical emergency, and all healthcare professionals should be familiar with its recognition and acute and ongoing management. These guidelines have been prepared by the European Academy of Allergy and Clinical Immunology (EAACI) Taskforce on Anaphylaxis. They aim to provide evidence-based recommendations for the recognition, risk factor assessment, and the management of patients who are at risk of, are experiencing, or have experienced anaphylaxis. While the primary audience is allergists, these guidelines are also relevant to all other healthcare professionals. The development of these guidelines has been underpinned by two systematic reviews of the literature, both on the epidemiology and on clinical management of anaphylaxis. Anaphylaxis is a potentially life-threatening condition whose clinical diagnosis is based on recognition of a constellation of presenting features. First-line treatment for anaphylaxis is intramuscular adrenaline. Useful second-line interventions may include removing the trigger where possible, calling for help, correct positioning of the patient, high-flow oxygen, intravenous fluids, inhaled short-acting bronchodilators, and nebulized adrenaline. Discharge arrangements should involve an assessment of the risk of further reactions, a management plan with an anaphylaxis emergency action plan, and, where appropriate, prescribing an adrenaline auto-injector. If an adrenaline auto-injector is prescribed, education on when and how to use the device should be provided. Specialist follow-up is essential to investigate possible triggers, to perform a comprehensive risk assessment, and to prevent future episodes by developing personalized risk reduction strategies including, where possible, commencing allergen immunotherapy. Training for the patient and all caregivers is essential. There are still many gaps in the evidence base for anaphylaxis.

Positive reactions to placebo in children undergoing double-blind, placebo-controlled food challenge.

BACKGROUND: The gold standard in the diagnosis of food allergy is the double-blind, placebo-controlled oral food challenge (DBPCFC). During this challenge, patients receive the allergenic food and placebo on separate randomized days, while being monitored for clinical reactions. Interestingly, some reactions are assessed as positive although the patients had received placebo. The aim of our study was to analyze incidence and characteristics of positive placebo reactions during DBPCFCs. METHODS: In food-allergic children, we retrospectively analyzed positive placebo reactions in DBPCFCs in 740 placebo challenges in our department. Individual characteristics were compared, such as age or IgE levels, as well as clinical symptoms. RESULTS: Of all placebo challenges, 2.8% (21 of 740) were assessed as positive. Young children (age ≤ 1.5 years) had more (P = 0.047) positive placebo challenges (4.0%) compared to older children (age > 1.5 years; 1.5%). Children with positive placebo challenges had higher levels of total IgE (median 201 kU/L) compared to negatively classified children (median 110 kU/L). In children with positive placebo reactions, skin symptoms were observed significantly more often, with a worsening of atopic eczema (AE) as the most reported symptom. CONCLUSION: Placebo reactions in DBPCFC are not common. Worsening of AE is the most frequent clinical reaction associated with positive placebo challenges, and young children (age ≤ 1.5 years) seem to be affected more often. Therefore - contrary to current recommendations - DBPCFC tests should be considered in infants and young children, especially those with a history of AE.

Management of anaphylaxis: a systematic review.

To establish the effectiveness of interventions for the acute and long-term management of anaphylaxis, seven databases were searched for systematic reviews, randomized controlled trials, quasi-randomized controlled trials, controlled clinical trials, controlled before-after studies and interrupted time series and - only in relation to adrenaline - case series investigating the effectiveness of interventions in managing anaphylaxis. Fifty-five studies satisfied the inclusion criteria. We found no robust studies investigating the effectiveness of adrenaline (epinephrine), H1-antihistamines, systemic glucocorticosteroids or methylxanthines to manage anaphylaxis. There was evidence regarding the optimum route, site and dose of administration of adrenaline from trials studying people with a history of anaphylaxis. This suggested that administration of intramuscular adrenaline into the middle of vastus lateralis muscle is the optimum treatment. Furthermore, fatality register studies have suggested that a failure or delay in administration of adrenaline may increase the risk of death. The main long-term management interventions studied were anaphylaxis management plans and allergen-specific immunotherapy. Management plans may reduce the risk of further reactions, but these studies were at high risk of bias. Venom immunotherapy may reduce the incidence of systemic reactions in those with a history of venom-triggered anaphylaxis.

Think twice: misleading food-induced respiratory symptoms in children with food allergy.

Reported food-related symptoms of patients may sometimes be misleading. A correct delineation of food-induced symptoms is often difficult and various differential diagnoses have to be considered. We report on two cases of food-induced, predominantly respiratory symptoms (in one case life-threatening) in children with food allergy. First, a two-year-old boy with no history of allergies and suspected foreign body aspiration which was finally diagnosed as an anaphylactic reaction to fish, and secondly a six-year-old girl with multiple food allergies and allergic asthma who during an electively performed oral food challenge developed severe respiratory distress, drop in blood pressure, and asphyxia not due to an anaphylactic reaction but due to choking on an unnoticed sweet. These two cases represent challenging, life-threatening symptom constellations involving food-induced reactions in food allergic children, reminding us to question first impressions.

Peanut allergen in house dust of eating area and bed--a risk factor for peanut sensitization?

It has been hypothesized that high environmental exposure to peanut allergens may be a potent risk factor for cutaneous sensitization. Therefore, we wanted to investigate whether peanut proteins are detectable in house dust of different household areas. Peanut levels of dust samples were measured with ELISA. Overall, peanut was detectable in 19 of 21 households in the eating area and/or in bed. The frequency of peanut consumption correlated with peanut levels. Forty-eight hours after intentional peanut consumption, peanut levels were highly increased. Nevertheless, further research is required to prove whether peanut allergen in house dust can cause sensitization via skin.

The epidemiology of anaphylaxis in Europe: a systematic review.

BACKGROUND: Anaphylaxis is an acute, potentially fatal, multi-organ system, allergic reaction caused by the release of chemical mediators from mast cells and basophils. Uncertainty exists around epidemiological measures of incidence and prevalence, risk factors, risk of recurrence, and death due to anaphylaxis. This systematic review aimed to (1) understand and describe the epidemiology of anaphylaxis and (2) describe how these characteristics vary by person, place, and time. METHODS: Using a highly sensitive search strategy, we identified systematic reviews of epidemiological studies, descriptive and analytical epidemiological investigations, and studies involving analysis of routine data. RESULTS: Our searches identified a total of 5,843 potentially eligible studies, of which 49 satisfied our inclusion criteria. Of these, three were suitable for pooled estimates of prevalence. The incidence rates for all-cause anaphylaxis ranged from 1.5 to 7.9 per 100,000 person-years. These data indicated that an estimated 0.3% (95% CI 0.1-0.5) of the population experience anaphylaxis at some point in their lives. Food, drugs, stinging insects, and latex were the most commonly identified triggers. CONCLUSIONS: Anaphylaxis is a common problem, affecting an estimated 1 in 300 of the European population at some time in their lives. Future research needs to focus on better understanding of the trends across Europe and identifying those most likely to experience fatal reactions.

The dark side of stem cells: triggering cancer progression by cell fusion.

The phenomenon of cell fusion plays a crucial role in a plethora of physiological processes, including fertilization, wound healing, and tissue regeneration. In addition to this, cell fusion also takes place during pathophysiological processes such as virus entry into host cells and cancer. Particularly in cancer, cell fusion has been linked to a number of properties being associated with the progression of the disease including an increased proliferation rate, an enhanced metastatogenic behavior, an increased drug resistance and an increased resistance towards apoptosis. Although the process of cell fusion including the molecules to be involved-in is not completely understood in higher organisms, recent data revealed that chronic inflammation seems to be strong mediator. Since tumor tissue resembles chronically inflamed tissue, it can be concluded that cell fusion between recruited macrophages, bone marrow-derived cells (BMDCs), and tumor (stem) cells should be a common phenomenon in cancer. In the present review, we will summarize how a chronic inflamed microenvironment could originate in cancerous tissues, the role of M2-polarized tumor associated macrophages (M2-TAMs) within this process and how fusion between macrophages and BMDCs will trigger cancer progression. A particular emphasis will be drawn on recurrence cancer stem cells (rCSCs), which will play a pivotal role in "oncogenic resistance" and which might originate from fusion events between tumor (stem) cells and BMDCs.

Characterization and analysis of migration patterns of dentospheres derived from periodontal tissue and the palate.

BACKGROUND AND OBJECTIVE: Stem cells derived from periodontal and palatal tissues may be useful for regenerative therapies of periodontal tissues. In addition to the use of single periodontium-derived stem cells (pdSCs) and palatal-derived stem cells (paldSCs), the application of pdSC and paldSC dentospheres, providing a pool of vital stem cells, may be a useful approach. As cell migration is a prerequisite for stem cells to regenerate a three-dimensional tissue environment, we characterized pdSCs and paldSCs and investigated the migratory activity of dentospheres within a three-dimensional environment. We also investigated the capacity of the dentospheres to grow on zirconium dioxide surfaces. MATERIAL AND METHODS: The capacity of pdSCs and paldSCs to differentiate into the neuronal and osteogenic lineages was proved by RT-PCR and immunohistochemistry through the detection of specific lineage markers, such as alkaline phosphatase, glutamate decarboxylase 1 (also known as GAD67, the 67-kDa isoform of glutamate decarboxylase), neurofilament-M and ß-III-tubulin. The expression profile of surface molecules on pdSCs and paldSCs was analyzed by flow cytometry. Adhesion and growth of pdSC/paldSC dentospheres on zirconium dioxide surfaces were determined using confocal laser-scanning microscopy. The migratory behavior of the cells was analyzed using a three-dimensional collagen matrix migration assay. RESULTS: Both pdSCs and paldSCs were positive for epidermal growth factor receptor, CC chemokine receptor 2 and CXC chemokine receptor 4 expression and were able to grow on zirconium dioxide surfaces. Cell-migration experiments revealed that both stem-cell populations responded similarly to epidermal growth factor (EGF), monocyte chemotactic protein 1 (MCP-1) and stromal cell-derived factor 1alpha (SDF-1α). Stimulation with EGF resulted in an increased migratory activity of both stem-cell types, whereas the locomotory behavior of the cells was impaired by both MCP-1 and SDF-1α. CONCLUSION: Dentospheres represent a pool of vital pdSCs/paldSCs. As a result of the migratory activity demonstrated, along with the capacity to grow on zirconium dioxide surfaces, dentospheres may be useful for regenerative purposes in periodontal tissues.